Color-developing composition containing an antioxidant

ABSTRACT

Color-developing compositions comprising a primary aromatic amine color-developing agent and as an antioxidizing agent certain linear compounds that are capable of existing in equilibrium with an enol form of said compound and that are not capable of intramolecular cyclization are advantageously used for color development because substantially less color-developing agent is lost from aerial oxidation than is lost from color developer compositions containing prior art antioxidants without the undesirable reduction in pH produced in prior art developer compositions by prolonged exposure to air.

United States Patent CONTAINING AN ANTIOXIDANT 19 Claims, No Drawings[1.8. CI 96/56, 96/66.4, 96/55 Int. Cl G03c 7/00, G03c 5/30 Field ofSearch 96/56, 66.4, 55

[56] References Cited UNITED STATES PATENTS 2,356,486 8/1944 Weissbergeret al 96/56 2,691,589 10/1954 l-lenn et al. 96/66.1 2,875,049 2/1959Kridel 96/55 3,300,305 l/1967 Pesch et a1 96/22 Primary Examiner-NormanG. Torchin Assistant ExaminerMary F, Kelley Anomeyswilliam H. J. Kline,James R. Frederick and Ray Carter Livermore ABSTRACT: Color-developingcompositions comprising a primary aromatic amine color-developing agentand as an antioxidizing agent certain linear compounds that are capableof existing in equilibrium with an enol form of said compound and thatare not capable of intramolecular cyclization are advantageously usedfor color development because substantially less color-developing agentis lost from aerial oxidation than is lost from color developercompositions containing prior art antioxidants without the undesirablereduction in pH produced in prior art developer compositions byprolonged exposure to air.

ANTIOXIDANT This invention relates to photography, compositions formaking photographic developer solutions and methods for stabilizingphotographic developer solutions against aerial oxidation.

The aqueous alkaline developer solutions used to develop the latentimage in image-exposed silver halide emulsions are usually held inphotographic processing machine tanks that are open to the air and areaerated by exposure to the air and by the passage of photographic filmor paper through the solutions. Unprotected solutions must be replacedoften and require a high rate of replenishment with fresh developersolution to replace developing agent and other oxidizable chemicals thatare destroyed by aerial oxidation. Overcoming the effects of aerialoxidation by replacing aerially oxidized developer solutions is not onlyexpensive from the standpoint of labor, time and chemical costs but alsocreates additional water pollution problems where these solutions aredisposed. The aerial oxidation of developer solutions is particularlyserious in color developer solutions for a number of reasons including lthe more exacting sensitometric requirements, (2) the more expensivechemicals including developing agent, dye-forming couplers when used inthe developer solution and other addenda, (3) the developing agents usedare usually more subject to oxidation, (4) the higher pH levels usuallyused in color developer solutions, etc.

Various compounds have been used as color developer additives in aneffort to minimize aerial oxidation of the developing agent. Forexample, British Pat. No. 886,269 cites the use of Z-methylcyclammoniumsalts for this purpose. The patent adds that some of the examples couplewith oxidized color developer to form dyes which must be removed fromthe emulsion. In addition, the compounds cited as examples are notreadily available. U.S. Pat. No. 2,728,669 cites the use of Dextrose andp-hydroxyphenylglycine as antioxidants adding, however, that theydecrease the development potential of the developer solution. In U.S.Pat. No. 2,401,7l3 the use of ascorbic acid is advocated. However, alater patent (U.S. Pat. NO. 2,923,627) points out that ascorbic acid isstable for only 2 to 3 hours and another patent (British Pat. No.782,304) adds that ascorbic acid is so unstable that its presence mustbe controlled by a specific addition of ascorbic acid solution as thecompound decomposes. Oxytetronic acids are mentioned in British Pat. No.782,304 as being cheap antioxidants, but in U.S. Pat. No. 2,923,627their effectiveness is found to be limited to 4 hours. Hydroxylamine andN,N-substituted hydroxylamines are also recommended in a number ofpatents. Hydroxylamine, however, also decreases development potential(U.S. Pat. No. 2,656,272) and also decomposes readily even as thecrystalline material (German Pat. No. 976,605). Substitutedhydroxylamines are relatively more expensive and still havedisadvantages which will be pointed out below.

Although a large number of compounds with a great range of structureshave been proposed as antioxidants for developer solutions, at present,only hydroxylamine is known to be in common use as an antioxidant incolor developers. Substituted hydroxylamines and ascorbic acid have verylimited use in photographic applications.

Hydroxylamine and hydroxylamine derivatives have the followingdisadvantages that have not been mentioned herein previously.

I. Hydroxylamine acts as a silver halide solvent (in a manner similar tothat of ammonia and other amines) thereby causing physical development.It also causes severe fog in certain emulsions as well as mismatchedcontrasts. Developer solutions containing hydroxylamine also experiencea buildup of ammonia because of the instability of hydroxylaminesolutions. The ammonia is a silver halide solvent which also causes fog.Even at safe" levels of hydroxylamine. lt-ls possible to build up anundesirable ammonia concentration.

2. Developer solutions undergo a slight drop in pH on standing byabsorption of carbon dioxide from the air. When hydroxylamine or itsderivatives are added to the developer, this pH drop is enhanced,especially when the solution is not at the maximum buffering pH of itsconstituents.

3. l-lydroxylamine is toxic and can cause serious reactions in humansupon repeated contact.

From the above discussion it is'obvious that better antioxidants fordeveloper compositions are desired.

It is therefore an object of our invention to provide a novel class ofantioxidants that are valuable for protecting developer compositionsagainst aerial oxidation for more extended periods of time than theprior art antioxidants without the disadvantages posed by the prior artantioxidants.

Another object of our invention is to provide novel improvedcolor-developing solutions.

Another object of our invention is to provide a novel colordevelopingsolution which is substantially more stable to aerial oxidation as aresult of incorporating one of our antioxidizing agents.

Another object of our invention is to provide novel color developersolutions which are more stable to pH change upon prolonged exposure toair than are solutions containing the usual prior art antioxidants.

Another object of our invention is to provide novel colordevelopingsolutions containing our antioxidizing agents which are characterized byproducing better photographic speeds and densities than thecorresponding color-developing solutions containing either noantioxidants or antioxidants of the prior art.

Still another object of our invention is to provide a novel means forprotecting color developer solutions against aerial oxidation for alonger period of time than is possible with prior art means and to dothis with a minimum of sensitometric changes which are characteristic ofprior art means.

These and still other objects of our invention will become obviousfrom'a consideration of the following specification and claims.

These and other objects of our invention are obtained by making andusing our color developer compositions comprising a primary aromaticamine color-developing agent and as an antioxidant for said colordeveloping agent a linear compound having the formula:

wherein R represents hydrogen, the carboxy group, alkyl having from oneto two carbon atoms (e.g., methyl, ethyl) and hydroxyalkyl having fromone to two carbon atoms (e.g., hydroxymethyl, 2-hydroxyethyl andl-hydroxyethyl) and R represents hydrogen, the carboxy group, thehydroxymethyl group and the formyl group, such that when R representscarboxy, R is nothyd'roxymethyl and such that when R is carboxy orformyl, R is not hydroxyalkyl, and such that said compound is capable ofexisting in equilibrium with an enol form of said compound and is notcapable of intramolecular cyclization.

Our compositions usually contain sufficient color-developig agent andsufiicient antioxidizing compound to produce a solution having aconcentration of from about 0.5 gram per liter to about 14 grams perliter of said developing agent and from about 0.1 gram per liter toabout 20 grams per liter of said antioxidant. Our preferred compositionscontain enough antioxidant to give a concentration when dissolvedin'water of from about 0.5 gram per liter to about 15 grams per literand an especially useful range of concentrations is from about 1 gramper liter to about 5 grams per liter of our antioxidizing agent.

We have found that use of our antioxidizing agents of formula l in colordeveloper compositions gives more protection to the color-developingagent against aerial oxidation than does hydroxylamine without thedisadvantages posed by hydroxylamine. For example, the pH of our colordeveloper solutions does not drop as does pH in prior artcolor-developing solutions containing hydroxylamine upon prolongedexposure to air. Our antioxidizing agents can be used at substantiallyhigher concentrations than is possible with hydroxylamine with noadverse effects from the developed dye image. Our antioxidizing agentscause very little fog when contained in either a fresh solution or in asolution that has been exposed for prolonged periods of time to the air.Unlike hydroxylamine or its decomposition products, our antioxidizingagents are not silver halide solvents. Our antioxidizing agents offormula 1 are nontoxic.

The following typical antioxidizing agents of our invention are includedin those of formula I.

Antioxidizing Agent Name 1 Dihydroxyacetone (i.e.. 1,3-

Dihydroxypropanone) 2 Glycolaldehyde (i.e.,

a-Hydroxyacetaldehyde) 3 Glyceraldehyde (i.e.,

2 ,3-1)ihydroxypropion-aldehyde 4 Dihydroxymaleic acid These compoundsillustrate compounds of the formula:

in which the values of R and R, are as follows:

Our antioxidizing agents are used advantageously in color developercompositions containing any of the well-known primary aromatic aminesilver halide developing agents, such as the P-Phenylenediaminesincluding the alkyl phenylenediamines and alkyl toluene diamines. Thesedeveloping agents are usually used in the salt form such as thehydrochloride or sulfate which are more stable than the amine. Theaminophenols and their substitution products may also be used ascolor-developing agents when the amine group is unsubstituted. TheN-alkyl sulfonamido alkyl-p-phenylenediamine agents of US. Pat. No.2,193,015 are also very useful. All of the developing agents have anunsubstituted amino group which enables the oxidation product of thedeveloper to couple with the color-forming products that form a dyeimage. Included among the color developers are, such typicalillustrative examples as the following:

1. N-(4-Amino-3-methylphenyl)morpholine 2.4-Amino-N-ethyl-N-carbamoylmethylaniline 3.4-Amino-3-chloro-N,N-diethylaniline 4.4-Amino-3-rnethyl-N-ethyl-N-carbamoylmethylaniline 5.N-(4-Aminophenyl)piperidine 6. 4-Amino-N-ethyl-N-(B-methoxyethyl)aniline7. 4-Amino-N-ethyl-N-(fl-acetamidoethyl)aniline 8.4-Amino-N-ethyl-N-(N-methyl-B-methylsulfonamidoethyl)aniline 9.4-Amino-N-ethy1-N-(B-ethoxyethyl)aniline l0.N-(4-Amino-3-methylphenyl)piperidine l I.4-Amlno-Z-methoxy-S-methyl-N,N-diethylaniline 12.4-Amlno-N,N-dlmethylanlllne l3.4-Amlno-N-ethyl-N-tetrahydrofurturylaniline 14.4-Amino-N-methyl-N-ethylaniline 15. 4-Amino-N-methyl-N-(n-butyl)aniline16. 4-Amino-N-methyl-N-(n-propyl)aniline 17.4-Amino-3-methyl-N-ethyl-N-(N-methyl-B-methylsulfonamidoethyl)aniline18. 4-Amino-N,N-diethylaniline l9.4-Amino-3-methylsulfonamidomethyl-N,N-

diethylaniline 20. 4-Amino-N-ethyl-N-(B-methylsulfonamidoethyl)aniline21 4-Amino-3-hydroxymethyl-N,N-diethylaniline 22.4-Amino-N-ethyl-N-(n-propyl)aniline 23.4-Amino-3-(B-acetamidoethyl)-N,N-diethylaniline 24.4-Amino-3-(B-hydroxyethyl)-N,N-diethylaniline 25.4-Amino-3-(B-aminoethyl)-N,N-diethylaniline 26.4-Amino-N-ethyl-N-(B-hydroxyethyl)aniline 27.4-Amino-N,N-di(n-propyl)aniline 28.4-Amino-3-methyl-N-methyl-N-(fi-methylsulfonamidoethyl)aniline 29.4-Amino-3-ethy1-N,N-diethylaniline 30. 4-Amino-3-(N-methyl-Bmethylsulfonamidoethyl)- N,N-diethylaniline 3 l.1-(4-Aminophenyl)pyrrolidine 32.4-Amino-3-methyl-N-ethyl-N-tetrahydrofurfurylaniline 33.4-Amino-3-(B-methylsulfonamidoethyl)N,N-

diethylaniline 34. 4-Amino-3-acetamido-N,N-diethylaniline 35.4Amino-3-methyl-N-ethyl-N-(B-methylsulfonamidoethyl)aniline 3 6.4-Amino-3 -methyl-N,N-diethylaniline 37.6-Amino-1-(B-methylsulfonamidoethyl)-l ,2,3 ,4-

tetrahydroquinoline 38.4-Amino-3-methyl-N-ethyl-N-(fi-hydroxyethyl)aniline 39.6-Amino-1-ethyl-1,2,3 ,4-tetrahydroquinoline 40.4-Amino-3-ethoxy-N-ethyl-N-(N-methyl-B-methylsulfonamidoethyl)aniline4-Amino-3-ethoxy-N-ethyl-N-(B-methylsulfonamidoethyl)aniline 42.4-Amino-3-methoxy-N,N diethylaniline 43.4-Amino-3-ethoxy-N,N-diethylaniline 44.4-Aminc-3-dimethylamino-N,N-diethylaniline 45.4-Amino-3-ethylamino-N,N-diethylaniline In addition to thecolor-developing agent and our antioxidant of formula I ourcolor-developing compositions comprise any addenda commonly found incolor developer solutions, such as, water, an alkali such as, alkalimetal carbonates, alkali metal borates, etc., alkali metal sulfites',alkali metal sulfates, alkali metal bromides, alkali metal iodides,silver halide solvents, antifoggants, diffusible dye-forming couplers,diffusible competing couplers, thickening agents, e.g., carboxymethylcellulose, carboxy lower alkyl substituted cellulose, etc.

The following examples are included for a further understanding of ourinvention.

Example 1 Three 1,100 ml. solutions of a color developer of thefollowing composition are labeled A, B and C.

Benzyl alcohol 5.0 ml. Sodium hexarnetaphosphate 2.5 g. Sodium sulfite1.85 g. Sodium bromide 1.40 g. Potassium iodide 0.5 mg. Sodium hydroxideg. Sodium tetraborate [011,0 44.9 g. 4-AminO-S-methyI-N-ethyl-N-fl-(methanesulfonamido)ethyl aniline sesquisulfate hydrate 6.1 Water tol 1.

Solution A is used as a control. Two grams of hydroxylamine sulfate areadded to solution B, and 2 grams of dihydroxy acetone are added tosolution C. The pl-ls of solutions 8 and C are adjusted to the pH ofsolution A, i.e., 10.60. The solutions A. B and C are allowed to standin uncovered containers. The volume of each solution is maintained at1,100 ml. by

' agent in solution C than-the hydroxylamine in solution B over waterreplenishment to compensate for evaporation. After 5 and days,respectively, the changes of their pH and the concentration ofcolor-developing agent (i.e., 4-amino-3-methyl-N-ethyl-N-B-(methanesulfonamido)ethylaniline sesquisulfate nidealkahmetal bromide bleach solution and a conventional alkali metalthiosulfate solution is used as a fix in the process. The thresholdspeed and maximum density of the red, green and blue images in thestrips are determined and the speed and TABLE 3 Threshold speed changeMaximum density change Strip Days Red Green Blue Red Green Blue 1b.. 50. 0. 13 0. l8 0. 28 0. 06 0. 04 10.. 10 0. 64 O. 0. 13 0. 64 0. l7 0.22 2b 5 0. 30 0. l2 0. 15 0. 30 0. 06 0. 20 2c... 10 0. 48 -0. l. 0. 230. 0. l4 0. 37 3b 5 0. 22 0. 09 0. 10 0. l6 0. 05 0. 04 30.. 10 -0. 280. l5 0. 20 0. 23 --0. 06 0. l0

hydrate are determined from 100 ml. samples of A, B and C- and recordedin table 1. The remainder of the processing solu- 1 tions is usedforprocessing as shown in example 2.

The results in table 1 show that the hydroxylamine in solution B causeda substantially greater loss in pH than did dihydroxy acetone insolution C. Solution C showed essentially the same loss in pH as did thecontrol solution A. Aerial oxidation of developing agent in solutions Band C is substantially reduced by the hydroxylamine and the dihydroxyacetone, respectively, compared to the unprotected control solution A.Dihydroxy acetone gives more antioxidant protection to the developingthe 5-day period and about the same protection over the 10- day period.

Example 2 Nine strips of a conventional multicolor, multilayer colorfilm such as is described in the example of Hanson US. Pat. No.2,449,966 containing incorporated color-forming couplers are labeled 1a,lb, 10, 2a, 2b, 20, 3a, 3b and 30, respectively. These strips areidentically exposed to a neutral scale test object and developed (14minutes at 75 F.) by treating the strips as indicated in table 2 inthe-developer solutions A, B and C described in example 1.

A conventional acetic acid-sodium acetate solution is used as the acidstop bath, a conventional formalin hardener solution is used forhardening, a conventional alkali metal ferricyamaximum density lossescaused by use of the 5- and 10-dayold solutions are listed in table 3.

The results show that solution C protected by our antioxidantdihydroxyacetone gave better speeds in processed film than did solutionsB and A after 5 days and after 10 days storage of the solutions. Theimprovement in film speed from use of our developer solution C isparticularly noticeable in the red speed which is maintained closer tothe green and blue speeds than in the films processed with eitherdeveloper solution A or B. The'data show that the D max losses for red,green and blue are substantially lower for strips 3b and 3c processedthrough our color developer C containing dihydroxy acetone than instrips 2b, 2c or control strips lb and 1c. The improvement produced byour developer solution is most pronounced in the maximum density of thecyan dye image. The greatly improved stability of our color developersolution to the effects of aerial oxidation as demonstrated by improvedsensitometric results provides a valuabletechnical advance.

Example 3 Seven l-liter solutions are made identically as solutions 1through 7, respectively, having the composition:

Bcnzyl alcohol 12.0 ml. Diaminopropanol.tetraacclic acid 3.0 g. Sodiumsulfitc 2.0 g. Sodium bromide 04 g. Sodium chloride 0.7 g. Sodiummetaborate 8H,() 45.0 g. 4-Aminn-3methyl-N-cthyl-Nfi-(methancsulfonamido)clhylanilinu sesquisulfaie hydrate (developingagent) 5.0 g. Water to l 1.

Solution Nov 1 having a pH of 10.60 is used as a control. Two grains perliter of the compounds indicated in table 4, are added to the othersolutions, and their pH's adjusted to 10.60. Five hundred-ml. portionsof these solutions are stored for 10 days in l-liter open beakers. Atthe end of this time the volume of solution is brought up to 500 ml.with water and analytical determinations are made of pH andconcentration of the developing agent remaining in the solutions. Anaverage of two developing agent concentration analyses is used incomputing the percent loss in developing agent concentration based onthe analyzed concentration in a fresh mixed control solution. 1

TABLE 4 Afiu' Hi Dav hiposurc in A" loss in Lactic acid, erythrose andacetoin are compounds that are outside our invention but have structuresthat are similar to compounds of our invention. The structures are asfollows:

011 O Lactic acid: CH3CH-(J-OH H 0H 0 Erythrose: HOCHzCH( 3H-CH OH 0Acetoin: CHat'IH-iI-CH:

The results show that very closely related compounds. lactic acid,erythrose and acetoin give very little if any antioxidant protection tothe developing agent when subjected to days aerial oxidation. It is notobvious from these data that the compounds of our invention, such as,dihydroxy acetone, glyoxaldehyde, etc., give excellent protection to thedeveloping agent against oxidation. Not only is hydroxylamine arelatively poor antioxidant compared to our compounds, such as,dihydroxy acetone and glyoxaldehyde, but the pH loss suffered in thehydroxylamine solution is about 1.7 to 1.8 times the pH loss in oursolutions.

Example 4 Examples 1 and 2 are repeated using glycolaldehyde,glyceraldehyde and dihydroxymaleic acid in place of dihydroxyacetone.The results obtained show that color developer solutions containingthese compounds can be subjected to aeriation and will undergosubstantially less loss in pH and loss in developing agent concentrationthan the developer solution containing hydroxylamine. Aeriation of ourdeveloper solutions causes less of a shift in the sensitometric resultsof film processed in them than aeriation of the developer solutioncontaining hydroxylamine.

Example 5 Examples 1 and 2 are repeated using developing agents from 1through 45, producing results similar to those demonstrated in examples1 and 2.

Our antioxidants of formula I are advantageously used in developersolutions at concentrations in the range from about 0.1 g./l. to about20 g./l., with the preferred concentration range from about 0.5 g./l. toabout g./1.

Example 6 Three l-liter solutions are made and identified as A, B and C.Solution A has the composition of solution A in example 1. Solution Bhas the composition of solution A and has in addition 5 g./l. ofhydroxylamine sulfate. Solution C has the composition of solution A andhas in addition 5 g./l. of dihydroxyacetone. Three strips labeled 1, 2and 3 of a conventional multicolor, multilayer color film such as isdescribed in the example of Hanson US Pat. No. 2,449,966 containingcolorforming couplers are given identical exposures. The exposed strips1, 2 and 3 are developed 14 minutes at 75 F. in freshly prepareddeveloper solutions A, B and C, respectively, and then the processing ofthe developed strips is completed with the acid stop, formalin hardener,wash, bleach, wash, fix, wash and drying steps described in example 2.Sensitometric curves relating developed cyan dye image densities withthe corresponding image exposure steps are made for the processedstrips. A comparison of the sensitometric curves for strips 1 and 2shows that 5 g./l. hydroxylamine causes in strip 2 an increase of 0.12in fog (minimum density) over the fog in control strip 1. Also thehydroxylamine produces an appreciable loss in contrast. A comparison ofthe sensitometric curves for strips 1 and 3 shows that 5 g./l. ofdihydroxyacetone produces only a 0.06 increase in fog and substantiallyno change in contrast over the control. In color photography, it isimportant that the cyan, magenta and yellow image reproductions haveessentially the same contrast. A loss in cyan dye image contrast such asis produced by the addition of 5 g./l. of hydroxylamine can produce acontrast mismatch between the images in the various layers which is veryundesirable and even unacceptable. As mentioned above, the addition of 5g./l. 0f dihydroxyacetone produces no shift in cyan dye contrast anddemonstrates valuable technical advance.

Example 7 Four l-liter solutions are made identically having thecomposition of control solution A in example 1. One liter of thisidentified in the immediate example as solution No. l is used as thecontrol. Two grams per liter of dihydroxy acetone are added to anotherliter of the solution identified as solution No 2. Two grams per literof dihydroxy maleic acid are added to another liter of the solutionidentified as solution No. 3 Two grams of hydroxylamine sulfate areadded to the fourth liter of the solution which is identified assolution No. 4. The pH s of solutions 2. 3 and 4 are each adjusted tothe pH of control solution No l. The solutions are allowed to stand inuncovered containers for 7 days Water is added to each container tobring the volume of each solution up to its initial 1 liter. The changein pH and in developing agent concentrations caused by the 7-day storageare recorded in table 5.

Results similar to those obtained in examples I, 3 and 7 are obtainedwhen these examples are repeated using developer solutions having thefollowing composition as the control solution and adding to this one ofthe compounds of formula I of our invention.

Benzyl alcohol 0-15 ml. Sodium hexametaphosphatc 2-3 g. Sodium sulfitel-2 g. Sodium bromide 0.2-2 g. Sodium chloride 0-l0 g. Potassium iodideO-lO mg. Sodium hydroxide 0-20 3. Sodium letraborate l0l-l,0 20-50 g.4-Amino-3-methyl-N-ethyl-n-B- (methanesulfonamido)ethyl anilinescsquisulfate hydrate 2-8 g. Water to l l.

The valuable antioxidant properties of our compounds shown in the aboveexamples are also demonstrated when these compounds are used in cyancolor developer solutions containing diffusible cyan dye-formingcouplers, in yellow color developer solutions containing diffusibleyellow dyeforming couplers and in magenta color developer solutionscontaining diffusible magenta dye-forming couplers that are used inprocessing multilayer, multicolor films that do not contain incorporatedcouplers. In these solutions our antioxidants not only prevent loss incolor-developing agent by aerial oxidation but also prevent loss of thecolor-forming coupler which would otherwise be used up by couplingreaction with the aerially oxidized color-developing agent.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We claim:

1. In a color-developing composition containing a primary aromatic aminecolor-developing agent and an antioxidant, the improvement comprisingthe antioxidant having the formula:

- Pu-CH-t'i-R wherein R represents a member selected from the classconsisting of hydrogen, the carboxy group, alkyl having one or twocarbon atoms and hydroxyalkyl having one or two carbon atoms; and Rrepresents a member selected from the class consisting of hydrogen, thehydroxymethyl group and the formyl group, such that when R representscarboxy, R is not hydroxymethyl and such that when R is formyl, R is nothydroxyalkyl and such that said compound is capable of existing inequilibrium with an enol form of said compound and is not capable ofintramolecular cyclization, enough of said antioxidant being added tosaid composition to give an antioxidant concentration in the range offrom about 0.1 g./1. to about 20 g./l. when dissolved in water.

2. A composition of claim 1 in which the antioxidant isdihydroxyacetone.

3. A composition of claim 1 in which the antioxidant is glycolaldehyde.

4. A composition of claim 1 in which the antioxidant is glyceraldehyde.

5. In a color-developing composition containing a primary aromatic aminecolor-developing agent, an alkali metal tetraborate, an alkali metalsulfite, and an antioxidant, the improvement comprising the antioxidanthaving the formula:

OH O rv-en-iLn wherein R represents a member selected from the classconsisting of hydrogen, the carboxy group, alkyl having one or twocarbon atoms and hydroxyalkyl having one or two carbon atoms; and Rrepresents a member selected from the class consisting of hydrogen, thehydroxymethyl group and the formyl group, such that when R representscarboxy, R is not hydroxymethyl and such that when R is formyl, R is nothydroxyalkyl, and such that said compound is capable of existing inequilibrium with an enol form of said compound and is not capable ofintramolecular cyclization, enough of said antioxidant being added togive an antioxidant concentration in the range of from about 0.5 g./l.to about 15 g./l. when dissolved in water.

6. The composition of claim 5 containing a sufficient amount of saidantioxidant to produce, when dissolved in water, a solution having aconcentration of from about 0.5 g./l. to about g./l. of saidantioxidant.

A a composition of claim 5 in which the antioxidant is dihydroxyacetone.

8. In a color-developing composition containing a primary aromatic aminecolor-developing agent and an antioxidant, the improvement comprisingthe antioxidant selected from the class consisting of dihydroxyacetone,glycolaldehyde and glyceraldehyde, a sufficient amount of saidantioxidant being added to give a concentration in the range of fromabout 0.1

g./l. to about 20 g./l. when dissolved in water.

9. In an aqueous alkaline color developer solution comprising a primaryaromatic amine color-developing agent, an alkali, and alkali metalsulfite, and an antioxidant, the improvement comprising the antioxidanthaving the formula:

I IV-CH-ii-R wherein R represents a member selected from the classconsisting of hydrogen, the carboxy group, alkyl having one or twocarbon atoms and hydroxyalkyl having one or two carbon atoms; and Rrepresents a member selected from the class consisting of hydrogen, thehydroxymethyl group and the formyl group, such that when R representscarboxy, R is not hydroxymethyl and such that when R is formyl, R is nothydroxyalkyl, and such that said compound is capable of existing inequilibrium with an enol formof said compound and is not capable ofintramolecular cyclization, enough of said antioxidant being added togive an antioxidant concentration in the range of from about 0.1 g./l.to about 20 g./l.

10. An aqueous alkaline color developer solution of claim 9 containingan alkali metal tetraborate.

11. An aqueous alkaline color developer solution of claim 9 containing adye-forming diffusible coupler.

12. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethylfN-fl-(methanesulfonamido)ethylamilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising the antioxidant being selectedfrom the class consisting of dihydroxyacetone, glycolaldehyde andglyceraldehyde, said antioxidant having a concentration in the range offrom about 0.1 g./l. to about 20 g./l.

13. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N-B-(methanesulfonamido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant the improvement comprising dihydroxyacetone as theantioxidant being in the range from about 0.1 g./l. to about 20 g./l.

14. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N-B-(methanesulfonamaido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising glycolaldehyde as theantioxidant being in the range of from about 0.1 g./l. to about 20 g./l.

15. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N-B-(methanesulfonamido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising glyceraldehyde as theantioxidant being in the range of from about 0.1 g./l. to about 20 g./l.

16. An aqueous alkaline cplor developer solution of pH 10.6 containingl. benzyl alcohol 12 ml.ll. 2. sodium sulfite 2 g./l. 3. sodiummetaboratc 8H,0 45 g./l. 4, 4-amino-B-methyl-N-ethyl-N-B-(methanesulfonamido)ethybanilinc sesquisulfate hydrate 5 gJl. and S.dihydroxyacetone 2 g./|.

17. An aqueous alkaline color developer solution of pH 10.6containing 1. benzyl alcohol 12 ml./l. 2. sodium sulfite 2 5.. 3. sodiummetaboratc EH 0 4S gjl. 4. 4-amino-3-methy|-N-cthyl-N-fi-(methanesulfonamido)ethyl-aniline sesquisulfate hydrate 5 g./l, and 5.glycolaldehyde Z gtl.

18. An aqueous alkaline color developer solution of pH 10.6containing 1. benzyl alcohol 12 ml./l. 2. sodium sulfite 2 g./l. 3.sodium metahoratc 8H,0 45 g./l. 4. 4-amine-S-methyl-N-ethyl-N-fi-(methanesulfonamido)ethyl-aniline sesquisulfate hydrate 5 g./l. and 5.glyceraldehyde 2 g./l.

19. An aqueous alkaline color developer solution of pH 10.6 containingl. benzyl alcohol 5,0 L/l 2. sodium sulfite r 1.85 gJl. 3. sodiumtetraborate [0H,() 44.9 g./l. 4. 4-amino-3-methyl-N-ethyl-N-fl;

tmethanesulfonamido)ethyl-aniline sesquisulfate hydrate 6.0 g./l. and 4.dihydroxyacetone 5.0 gJl.

2. A composition of claim 1 in which the antioxidant isdihydroxyacetone.
 3. A composition of claim 1 in which the antioxidantis glycolaldehyde.
 4. A composition of claim 1 in which the antioxidantis glyceraldehyde.
 5. In a color-developing composition containing aprimary aromatic amine color-developing agent, an alkali metaltetraborate, an alkali metal sulfite, and an antioxidant, theimprovement comprising the antioxidant having the formula: wherein Rrepresents a member selected from the class consisting of hydrogen, thecarboxy group, alkyl having one or two carbon atoms and hydroxyalkylhaving one or two carbon atoms; and R'' represents a member selectedfrom the class consisting of hydrogen, the hydroxymethyl group and theformyl group, such that when R represents carboxy, R'' is nothydroxymethyl and such that when R'' is formyl, R is not hydroxyalkyl,and such that said compound is capable of existing in equilibrium withan enol form of said compound and is not capable of intramolecularcyclization, enough of said antioxidant being added to give anantioxidant concentration in the range of from about 0.5 g./l. to about15 g./l. when dissolved in water.
 6. The composition of claim 5containing a sufficient amount of said antioxidant to produce, whendissolved in water, a solution having a concentration of from about 0.5g./l. to about 15 g./l. of said antioxidant.
 7. A composition of claim 5in which the antioxidant is dihydroxyacetone.
 8. In a color-developingcomposition containing a primary aromatic amine color-developing agentand an antioxidant, the improvement comprising the antioxidant selectedfrom the class consisting of dihydroxyacetone, glycolaldehyde andglyceraldehyde, a sufficient amount of said antioxidant being added togive a concentration in the range of from about 0.1 g./l. to about 20g./l. when dissolved in water.
 9. In an aqueous alkaline color developersolution comprising a primary aromatic amine color-developing agent, analkali, an alkali metal sulfite, and an antioxidant, the improvementcomprising the antioxidant having the formula: wherein R represents amember selected from the class consisting of hydrogen, the carboxygroup, alkyl having one or two carbon atoms and hydroxyalkyl having oneor two carbon atoms; and R'' represents a member selected from the classconsisting of hydrogen, the hydroxymethyl group and the formyl group,such that when R represents carboxy, R'' is not hydroxymethyl and suchthat when R'' is formyl, R is not hydroxyalkyl, and such that saidcompound is capable of existing in equilibrium with an enol form of saidcompound and is not capable of intramolecular cyclization, enough ofsaid antioxidant being added to give an antioxidant concentration in therange of from about 0.1 g./l. to about 20 g./l.
 10. An aqueous alkalinecolor developer solution of claim 9 containing an alkali metaltetraborate.
 11. An aqueous alkaline color developer solution of claim 9containing a dye-forming diffusible coupler.
 12. In an aqueous alkalinecolor developer solution containing 4-amino-3-methyl-N-ethyl-N- Beta-(methanesulfonamido)ethylaniline sesquisulfate hydrate, an alkali, analkali metal sulfite and an antioxidant, the improvement comprising theantioxidant being selected from the class consisting ofdihydroxyacetone, glycolaldehyde and glyceraldehyde, said antioxidanthaving a concentration in the range of from about 0.1 g./l. to about 20g./l.
 13. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N- Beta -(methanesulfonamido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising dihydroxyacetone as theantioxidant being in the range from about 0.1 g./l. to about 20 g./l.14. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N- Beta -(methanesulfonamaido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising glycolaldehyde as theantioxidant being in the range of from about 0.1 g./l. to about 20 g./l.15. In an aqueous alkaline color developer solution containing4-amino-3-methyl-N-ethyl-N- Beta -(methanesulfonamido)ethylanilinesesquisulfate hydrate, an alkali, an alkali metal sulfite and anantioxidant, the improvement comprising glyceraldehyde as theantioxidant being in the range of from about 0.1 g./l. to about 20 g./l.16. An aqueous alkaline color developer solution of pH 10.6 containing17. An aqueous alkaline color developer solution of pH 10.6 containing18. An aqueous alkaline color developer solution of pH 10.6 containing19. An aqueous alkaline color developer solution of pH 10.6containing
 1. benzyl alcohol 5.0 ml./l.
 2. sodium sulfite 1.85 g./l. 3.sodium tetraborate . 10H2044.9 g./l.4. 4-amino-3-methyl-N-ethyl-N- Beta-(methanesulfonamido)ethyl-aniline sesquisulfate hydrate 6.0 g./l. and4. dihydroxyacetone 5.0 g./l.